Neutral is Definition, device and purpose

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Kev lag luam hluav taws xob hluav taws xob yog ib qho kev lag luam complex, uas muaj ntau yam khoom. Txhawm rau kom txhua lub ntsiab lus ua haujlwm kom raug thiab ua tiav nws txoj haujlwm, kev paub tseeb thiab kev nkag siab ntawm cov txheej txheem ntawm lub cev uas tshwm sim hauv cov khoom siv fais fab yog tsim nyog. Ib txhia ntawm lawv piav tau yooj yim, yog li peb xav kom paub txog lub tswv yim xws li "neutral".

Lub hom phiaj dav dav ntawm cov xaim nruab nrab hauv transformer windings

Tsis yog ib qho, xoom point conductor kev sib txuas hauv peb-theem transformers lossis generators. Tam sim no, muaj 4 hom tseem ceeb ntawm xoom point txuas:

1. Ib leeg. Hom no yog tus cwj pwm los ntawm qhov tsis muaj qhov nruab nrab. Lub tswv yim txuas tseem ceeb rau kev nthuav qhia network yog daim duab peb sab. Nrog ib-theem lub ntiaj teb ua txhaum nyob rau hauv cov theem ua hauj lwm, lawv tsis hnov txog kev hloov ntawm lub zog noj. Hom no yog siv nyob rau hauv kev faib network.6-35 kV.
2. Resonance grounded. Qhov kev xaiv no suav nrog kev siv hauv av ntawm xoom point ntawm windings ntawm transformer lossis generator los ntawm arc-suppressing coils lossis reactors (DGK, DGR). Lub xub ntiag ntawm cov cuab yeej tshwj xeeb tau them nyiaj rau qhov nce qib tam sim no, zam kev nyuaj ntawm theem mus rau theem tsis ua haujlwm.
3. Ntxhais hmoob. Feem ntau hom nruab nrab siv hauv kev tes hauj lwm hauv tsev. Lub winding ntawm transformers nyob rau sab qis yog ua nyob rau hauv ib tug qhib lub hnub qub kev twb kev txuas thiab qhov nruab nrab point yog earthed los ntawm lub ntiaj teb voj ntawm transformer los yog transformer substation. Nyob rau hauv cov xwm txheej ntawm kab txhaum los yog ib-theem luv luv Circuit Court, ib tug muaj peev xwm yog tsim nyob rau hauv hwm rau lub ntiaj teb, uas activates kev tiv thaiv uas disconnects kab.
4. Ua tau zoo hauv av. Ib hom av nruab nrab, uas yog siv nyob rau hauv high-voltage tes hauj lwm ntawm 110 kV thiab saum toj no. Lub zero point ntawm lub hwj chim transformers thiab lub txim txhaum yog coj mus rau hauv av. Txhawm rau txhawm rau txhim kho kev tiv thaiv, cov cuab yeej siv ntxiv yog siv - ib kab nruab nrab ntawm lub ntiaj teb hloov pauv (ZON). Txoj haujlwm ntawm lub tshuab hloov pauv yog txiav txim siab los ntawm cov lus qhia hom. Rau kev faib tawm ntawm 6-35 kV, siv av los ntawm qhov tsis kam tiv thaiv qis.

Hom kev sib txuas ntawm windings ntawm lub zog transformers

Raws li tau sau tseg saum toj no, qhov nruab nrab yog qhov kev sib txuas ntawm qhov nruab nrab ntawm lub tshuab hluav taws xob peb theem lossis lub tshuab hluav taws xob. Txhawm rau txiav txim siab hom av, nws txaussaib cov tswv yim ntawm cov khoom siv fais fab. Rau qhov sib cais nruab nrab, daim duab kos duab yog daim duab peb sab.

Lwm cov kev xaiv yog siv los ntawm kev sib txuas ntawm cov neeg nruab nrab nruab nrab rau hauv av, DHA, tsis tshua muaj siab resistor. Cov yav tas yog tsuas yog siv nyob rau hauv substations uas hloov high voltage hluav taws xob hluav taws xob rau tsawg, neeg siv. Schematic daim duab - hnub qub.

Insulated nruab nrab hauv hluav taws xob tes hauj lwm

Siv hauv kev faib khoom siv 6-35 kV. Hais txog lub cev tshwm sim ntawm ib qho kev sib cais nruab nrab, qhov voltage nce mus rau linear. Lub hom phiaj tseem ceeb ntawm hom no yog txuam nrog cov ntsiab lus hauv qab no:

1. Lub network tsis kaw, nws tseem ua haujlwm. Cov neeg siv khoom ntawm cov theem uas tsis muaj lub voj voog siv ib-theem khoom siv hauv tsev kom txog rau thaum cov kab raug txiav. Tsis muaj qhov tsis sib haum xeeb hauv 0.4 kV tes hauj lwm, hauv tes hauj lwm 6-35 nws nce mus rau linear.
2. Kev siv cov tes hauj lwm zoo li no ntau zaus pheej yig dua los tswj, uas tso cai rau koj txuag nyiaj tseem ceeb ntawm kev faib hluav taws xob hluav taws xob.
3. Kev ntseeg siab, tshwj xeeb tshaj yog ntawm cov kab hluav taws xob overhead. Lub caij nplooj zeeg ntawm ceg yuav tsis tua lub feeder thiab xyuas kom nws ua tau zoo.

Qhov tsis zoo ntawm kev sib cais yog:

1. Nrog rau ib theem luv luv, lub network txuas ntxiv ua haujlwm, kev tiv thaiv tsis ua haujlwm, uas qee zaum ua rau muaj xwm txheej nrog cov pejxeem.
2. Qhov muaj cov txheej txheem ferroresonant thiab tshwm sim ntawm lub zog reactive, uas degrades qhov zoohluav taws xob zog.

Resistor thiab voltage ntawm 110 kV thiab saum toj no: pes tsawg taw tes ua li cas?

Kev siv av zoo yog hom tshwj xeeb ntawm cov neeg nruab nrab nruab nrab txuas nrog cov cuab yeej tshwj xeeb, uas yog siv rau hauv cov khoom siv hluav taws xob siab tshaj 1 kV. Rau kev faib cov tes hauj lwm, ib qho kev sib txawv nrog earthing los ntawm cov resistors uas tsis tshua muaj siab siv, uas muab cov kab kev sib txuas hauv ib theem ntawm lub ntiaj teb txhaum yam tsis muaj sij hawm ncua.

Cov kab hluav taws xob siab siab ntawm 110 kV thiab saum toj no kuj tseem siv cov lus qhia ntawm qhov nruab nrab, uas ua kom cov lus teb ceev ceev ntawm kev tiv thaiv. Txhawm rau kom muaj kev nkag siab zoo ntawm kev ua haujlwm "relay", txhua lub zog hloov hluav taws xob muaj cov cuab yeej tshwj xeeb ZON. Ib kem nruab nrab hauv av tseem muab kev tiv thaiv overload.

Grounding los ntawm qhov tsis muaj zog resistors

Kev siv cov resistors qis yog suav tias yog ib qho kev daws teeb meem zoo tshaj plaws rau kev nyab xeeb ntawm cov neeg hauv kev sib txuas, nrog rau kev tswj xyuas cov rwb thaiv tsev ntawm cov kab cable. Qhov kev siv ntawm kev tiv thaiv yuav nqa lub zero point mus rau cov cuab yeej tshwj xeeb, uas muaj qhov qis dua ohmic tsis kam thiab muab lub teeb liab tua kab. Lub feeder yog hloov tawm nrog lub sijhawm qeeb qeeb, uas yog ib qho zoo. Lwm tus muaj xws li:

• Ua ntej, qhov no yog qhov nruab nrab, uas, thaum "lub ntiaj teb" tshwm sim, txiav txim siab qhov kev puas tsuaj thiab tig tawm qhov xav taukab.
• Thib ob: tsis tas yuav muaj kev suav ntxiv thiab muab tso ua ke ntawm tsoomfwv daim ntawv qhia nrog txwv tsis pub muaj peev xwm rau kev xa xov sib txuas.

Qhov tsis zoo tseem ceeb ntawm hom av no:

1. Tsis ua haujlwm rau lub ntiaj teb siab tam sim no vim nws ua rau muaj teeb meem hauv substations uas tsis tshua muaj zog resistors raug teeb tsa.
2. Kev ua haujlwm qis ntawm cov kab nyiaj siv ua haujlwm, nrog rau cov kab nyob deb. Nyob rau hauv thawj rooj plaub, qhov me ntsis mus kom ze ntawm tsob ntoo ceg yuav ua rau lub feeder muab tua. Tshwj xeeb tshaj yog cuam tshuam nrog cov neeg siv khoom ntawm 1 tshwj xeeb, 1 thiab 2 pawg.
3. Kev kaw ntxiv uas tshwm sim vim kev ua haujlwm tsis raug ntawm kev tiv thaiv (tsis muaj kev rov kaw tsis siv neeg), txhais tau hais tias lub sijhawm poob qis hauv kev noj, cov khoom poob ntawm lub koom haum muab hluav taws xob.

dig muag grounding ntawm lub hwj chim transformers rau lub ntiaj teb

Txhua yam txuas nrog 0.4 kV faib network yog qhov nruab nrab nrog lub lag ntseg hauv av. Hom kev nthuav qhia muaj qhov tshwj xeeb thiab lub luag haujlwm ntawm kev ruaj ntseg. Thaum lub caij luv luv rau hauv av tshwm sim, kev tiv thaiv tau tshwm sim, tshwj xeeb, PN-2 kub hnyiab tawm lossis lub tshuab kaw. Hais txog lub network zoo li no, kev tiv thaiv kuj tseem raug tsim rau kev xaim hauv tsev thiab cov tsev. Ib qho piv txwv zoo tshaj plaws yog kev ua haujlwm ntawm RCD, uas ua kom pom cov dej ntws tawm.

Qhov zoo ntawm qhov tsis zoo no yog:

1. Zoo tshaj plaws rau kev faib hluav taws xob hluav taws xob, khaws tsev neeg thiab tshwj xeebib-theem/three-theem khoom.
2. Kev tiv thaiv Circuit Court tsis xav tau cov cuab yeej tshwj xeeb thiab kim. Kev txhais tau tias xws li fuses lossis Circuit Court breakers tuaj yeem tiv taus qhov luv luv rau hauv av.

Qhov tsis zoo suav nrog:

1. Kev tiv thaiv tsis zoo rau qhov luv luv luv. Nws yog ib qho tsim nyog los xam qhov tseeb ntawm ohmic tsis kam ntawm lub voj voog theem-zero thiab kev xaiv kom raug ntawm Circuit Court breakers lossis fuses.
2. Trip tsis tshwm sim yog tias tsis muaj qhov txhaum hauv ntiaj teb. Qhov no ua rau muaj kev phom sij rau tib neeg, uas raug kho los ntawm kev siv cov xov hlau insulated.

Resonantly grounded or compensated neutrals

Resonantly grounded neutrals feem ntau yog siv rau hauv kev sib txuas nrog qhov hluav taws xob ntawm 6-35 kV, qhov twg txoj kev sib txuas yog nqa los ntawm cov kab hluav taws xob. Kev sib txuas ntawm xoom taw tes yog nqa tawm los ntawm kev tshwj xeeb plunger lossis adjustable transformers RUOM. Xws li lub kaw lus tso cai rau koj los txiav txim siab qhov inductance hauv lub network thaum lub sijhawm luv luv Circuit Court, uas muab nyiaj them rau qib tam sim no.

Hom kev nruab nrab no txo qis kev pheej hmoo ntawm kev sib tsoo, kev hloov pauv ntawm ib theem luv luv mus rau ib qho kev sib tshuam. Qhov zoo rau qhov hluav taws xob 6-35 kV yog:

Qhov txiaj ntsig tseem ceeb yog cuam tshuam nrog lub hom phiaj ntawm cov khoom siv. High degree ntawm rwb thaiv tsev tiv thaiv ntawm cable kab nrog kev kho kom raug

Qhov tsis zoo ntawm lub network nrog hom nruab nrab yog:

1. nyuaj teeb tsa. Undercompensation lossis overcompensation yuav tshwm sim,uas yuav tiv thaiv kev siv cov khoom siv kom raug. Rau kev sib dhos, nws yog ib qho tsim nyog los xam qhov inductance ntawm cov tam sim no nyob ntawm qhov ntev ntawm txoj kab, lub zog ntawm cov transformers. Nyob rau hauv rooj plaub ntawm kev hloov cov tswv yim los yog ntxiv cov khoom siv fais fab, plunger transformers tsis tas yuav tiv nrog cov dej num.
2. Cov khoom siv kho tsis raug thiab hnav cov kab hluav taws xob siab ua rau muaj cov tshuaj tiv thaiv kab mob uas cuam tshuam nrog kev ua tsis tiav ntawm ntau ntu tsis muaj zog ntawm lub network.
3. nce hauv kev poob haujlwm uas tshwm sim thaum lub sijhawm ua haujlwm, nrog rau teeb meem kev nyab xeeb. Kev them nyiaj tam sim no hauv substation yog ua raws li hauv av.
4. Tsis muaj peev xwm txiav txim siab txoj kab qhov chaw luv luv tshwm sim. Cov txheej txheem ntawm kev xaiv lub feeder nrog "hauv av" yog ua los ntawm kev sib piv ntawm kev sib haum xeeb tam sim no, uas tsis yog ib txwm suav tias yog ib qho txiaj ntsig zoo ntawm kev tau txais cov ntaub ntawv txhim khu kev qha.

Neutral conductor thiab arc quenching coil, reactor

Qhov sib txawv ntawm qhov sib txawv hauv qhov nruab nrab ntawm qhov nruab nrab yog cuam tshuam nrog cov cuab yeej siv. Raws li tau sau tseg saum toj no, qhov xoom taw tes tuaj yeem nyob ntawm lub plunger-type arc quenching coil lossis ntawm lub reactor adjustable. Qhov sib txawv tseem ceeb yog txuam nrog cov ntsiab lus hauv qab no:

1. DGK suav tias them nyiaj los ntawm kev hloov kho ntawm plunger transformers. Kev teeb tsa yog siv los ntawm kev suav ntawm lub network tiag tiag los ntawm kev pabcuam tiv thaiv relay. Thaum lub ntiaj teb txhaum tshwm sim, cov tam sim no raug them raws li inductance. Cov txheej txheem tsis raug tswj lossis hloov kho, uasyog lub caij tsis kaj siab nyob rau hauv cov ntaub ntawv ntawm cov tsos ntawm "lub ntiaj teb" ntawm ob peb lub ntsiab lus ntawm cov kab sib txawv.
2. DGR - cov cuab yeej siv niaj hnub no, uas suav nrog kev siv cov tshuab tsis siv neeg los txiav txim siab lub network inductance. Ntawm cov kev xaiv nrov yog RUOM-hom reactors nrog SAMUR tuning. Kev siv lub sijhawm pov npav tiag tiag ua kom muaj peev xwm ua haujlwm txawm tias muaj ntau qhov txhaum hauv av.

Txawm hais tias muaj kev sib koom ua ke los yog insulated, txhua yam muaj nws qhov chaw hauv kev lag luam hluav taws xob niaj hnub no. Thiab kev paub txog cov yam ntxwv yuav tso cai rau koj los daws qhov teeb meem ntawm lub cev.